How flexible is the human voice? - a case study of mimicry

The investigation presented here is a case study of mimicry in which a professional impersonation artist imitated three well-known Swedish public figures. The speech material consisted of recorded material taped from radio/TV shows, imitations of these speeches in which the artist tried to mimic the speeches as closely as possible, and the same speech material recorded with the artist using his own natural voice. The aim of the study was to investigate how closely the imitations matched selected acoustic parameters of the original recordings. It was found that he was able to mimic global speech rate very closely, but timing at the segmental level showed little or no change in the direction of the targets. Mean fundamental frequency and variation matched the targets very closely. Target formant frequencies were attained with varying success. For two of the three target voices the vowel space of the imitation was intermediate between that of the artist's own voice and the target. In the third case there was no apparent reduction in distance. With respect to individual vowels it was generally, but not always, the case that the formant frequencies of the mimicked vowels were closer to the original than those of the artist's own voice.